AIX CDE must conceal, via the session lock, information previously visible on the display with a publicly viewable image.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-91237	AIX7-00-001101	SV-101337r1_rule		Medium

Description
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information.

Description

A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information.

STIG	Date
IBM AIX 7.x Security Technical Implementation Guide	2020-02-24

Details

Check Text ( C-90393r3_chk )
If CDE (X11) is not used on AIX, this is Not Applicable. Ensure that the screen saver and session timeout are not disabled. From the command prompt, run the following script: # AIX7-00-001101_Check.sh Note: This script is included in the STIG package. The above script should yield the following output: Checking config file /etc/dt/config/C/sys.resources... Missing config file /etc/dt/config/C/sys.resources Checking config file /etc/dt/config/POSIX/sys.resources... dtsessionsaverTimeout: 15 dtsessionlockTimeout: 30 Checking config file /etc/dt/config/en_US/sys.resources... dtsessionsaverTimeout: 15 dtsessionlockTimeout: 25 If the result of the script shows any config file missing, or any of the "dtsessionsaverTimeout" or "dtsessionlockTimeout" values is greater than "15", this is a finding.

Check Text ( C-90393r3_chk )

If CDE (X11) is not used on AIX, this is Not Applicable.

Ensure that the screen saver and session timeout are not disabled.

From the command prompt, run the following script:

# AIX7-00-001101_Check.sh

Note: This script is included in the STIG package.

The above script should yield the following output:

Checking config file /etc/dt/config/C/sys.resources...
Missing config file /etc/dt/config/C/sys.resources

Checking config file /etc/dt/config/POSIX/sys.resources...
dtsession*saverTimeout: 15
dtsession*lockTimeout: 30

Checking config file /etc/dt/config/en_US/sys.resources...
dtsession*saverTimeout: 15
dtsession*lockTimeout: 25

If the result of the script shows any config file missing, or any of the "dtsession*saverTimeout" or "dtsession*lockTimeout" values is greater than "15", this is a finding.

Fix Text (F-97437r3_fix)
From the command prompt, run the following script to set the default timeout parameters "dtsessionsaverTimeout:" and "dtsessionlockTimeout:" as "15" minutes: # AIX7-00-001101_Fix.sh Note: This script is included in the STIG package.